Raipur (Chhattisgarh), Aug 12 (ANI): Chhattisgarh Chief Minister Raman Singh on Saturday said that his Delhi visit was very fruitful and he invited President Ramnath Kovind and Vice President Venkaiah Naidu to Chhattisgarh to attend the ‘Raj Utsav’. The Chhattisgarh Chief Minister added that during the visit, he also met Bharatiya Janata Party President Amit Shah.